Field of the Invention
The present invention is based on the National Research and Development Project (10045212) and the Industrial Convergent Technology and Industrial Core Technology Development Project (IT Convergence) supported by the Ministry of Trade, Industry and Energy of Korea and the Korea Evaluation Institute of Industrial Technology.
The present invention relates to condition based maintenance in marine resource production equipment, and more particularly to a method and apparatus for managing failure modes for condition based maintenance in marine resource production equipment.
Description of the Related Art
With the recent acceleration in the consumption of resources due to industrial development, it is difficult to supply enough resources to satisfy the demand for resources through the development of onshore resources alone. For this reason, it is becoming more and more important to drill and produce resources, such as oil and gas, in the sea, particularly the deep sea.
In Korea, vessel type offshore plants are generally used. In the Gulf of Mexico, the North Sea, and the like, however, jack-up rig type, TLP type, and SPAR type offshore plants are also commonly used.
The task of determining whether to extend the life span of offshore plants that were installed after the year 1980 and have been operated for 25 years or more or whether to dismantle the offshore plants based on calculation of the remaining life span of the offshore plants has become more common since the year 2005. In DNVGL and ABS, the life span extension market is expected to expand, and related engineering services and software have been strengthened.
In fields related to systems for condition based maintenance in offshore plants, products from DNV, GE, SAS, and SIEMENS provide high CBM level functions, and Aker Solutions has released an engineering service based asset management system on the market.
The life spans of offshore plants that have been operated since the year 1980 are expiring all over the world. Oil companies have to choose whether to extend the life spans of their platforms or whether to order new platforms. Therefore, it is necessary to develop a total system that is capable of enabling the oil majors to determine whether to extend the life span of their platforms or to order new platforms. In addition, it is necessary to develop a condition based maintenance system through research on offshore plant industry characteristics in order to find offshore plant maintenance markets, which have expanded.
An offshore plant (e.g. an oil platform or an offshore platform) is a large-scale structure, which drills for oil, and extracts and stores oil and natural gas. The offshore plant may be configured to have a fixed type structure or a floating type structure based on the environments in which the offshore plant is used. In addition, the offshore plant may be configured to have a subsea structure, in which one or more oil wells are connected to the platform via oil or gas supply lines.
Drilling vessels, which are vessel type offshore plants, are used in the deep sea or in choppy waters, where it is not possible to install platforms. As of the year 2013, 79 such vessels are in operation, and 68 more vessels are under construction worldwide.
Floating production storage and offloading (FPSO) vessels are vessel type offshore plants configured to refine and store crude oil collected from platforms around the FPSO vessels and subsea lines. Such FPSO vessels were first operated by Shell in the year 1977, and as of the year of 2013 more than 200 FPSO vessels are being operated.
A dynamic positioning system (DPS) is a system that automatically maintains the position of a vessel and the direction of the bow of the vessel through a GPS signal using a propulsion system. The dynamic positioning system is the result of typical IT convergence technology in the shipbuilding and offshore plant industry.
Recently, in the offshore plant industry, it is a principal object to achieve the operation and the production in the deep sea. In order to withstand the deep sea environment, the average length and diameter of offshore plants have decreased, and the total cost of deep sea projects has increased due to the requirement for non-defective pipe lines and inhospitable installation environments.
Hereinafter, elementary technology for condition based maintenance in an offshore plant will be described with reference to the accompanying drawings.
FIG. 1 is a view illustrating elementary technology for condition based maintenance in an offshore plant.
The British Standard Institution defines a process for diagnosing equipment based on observed data regarding the state of facilities and determining the necessity and time for maintenance based on the diagnosis results as condition based maintenance (CBM).
FIG. 1 shows the classification of maintenance policies. CBM is a kind of preventive maintenance, and time based maintenance (TBM) is another kind of preventive maintenance. TBM is a maintenance policy based on the reliability of equipment, whereas CBM is a maintenance policy based on a predictive technique.
In time based maintenance (TBM), the inspection and repair of facilities are periodically performed at predetermined time intervals. If the repair of facilities is periodically performed at intervals shorter or longer than the original life span of the facilities in consideration of the difference in deterioration among the facilities based on operating conditions, the facilities may break down due to variation in deterioration among the facilities. As a result, the repair intervals may be shortened, and the number of parts to be repaired may be increased. In addition, the condition of the facilities is deteriorated whenever the facilities are repaired, whereby the reliability of the facilities is reduced. As a result, the number of parts to be repaired may be increased, whereby repair costs may be increased.
Predictive maintenance (PM) is a method for predicting the failure of equipment and maintaining the equipment by measuring and monitoring whether the equipment has physically changed. When engine oil is inspected, any changes in color are observed, and maintenance is performed based on the observation results.
Condition based maintenance or condition based preventive maintenance (CBM) is a method for quantitatively observing the deterioration of facilities based on facility diagnosis or a control management system (CMS), and repairing the facilities when it is observed that the facilities are abnormal, in place of periodic inspection and repair of the facilities.
In addition, periodic diagnosis is performed in place of periodic repair, as in TBM. That is, facility diagnosis or condition monitoring is performed instead of periodic repair. As a result, the state of facilities is quantitatively monitored, whereby it is possible to maximally prevent any increase in maintenance cost due to excessive maintenance while preventing failure of the facilities. However, it is necessary to make a heavy investment to acquire the equipment and systems necessary for diagnosis. In order to reduce the cost necessary to introduce the equipment and systems, therefore, information communication technology (ICT) must be introduced.
Table 1 indicates various failure mechanisms.
TABLE 1AbnormalStressDamagephenomenaConditionRotationCrackSurgingVibrationLoadPeelingWater hammerAbnormalsoundTemperatureDeformationCavitationGenerationof heatPressureFractureBeatingEmissionof lightSpeedWearWhirlingUltrasonicwavesAccelerationStickingLoosenessAftereffectsEnvironmentCloggingCurrentVoltage
If a facility or components of the facility are excessively stressed due to the various failure mechanisms indicated in Table 1, damage and abnormalities may occur, which lead to a reduction in the performance of the facility. According to the circumstances, the facility may malfunction, with the result that the facility may break down.
FIG. 2 is a view illustrating technology for condition based maintenance in a production plant.
Technology related to condition based maintenance in the production plant may be connected with the existing basis systems that have been operated to date, and may be mapped as shown in FIG. 2. A plant information monitoring system (information regarding operation quality, a control system, facilities, a lubrication system, a hydraulic system, and a working oil system) is indicated in Table 2.
TABLE 2Plant information monitoring system (information regardingoperation quality, a control system, facilities, a lubricationsystem, a hydraulic system, and a working oil system)ControlTransitionOperationsystemOnlinephenomenonSamplinginformationinformationmonitoringmonitoringinformation1. Line1. Flow rate1. Seismic1. Shaft1. Extent ofspeedinformationintensityvibrationpollution of2. Amount2. Temper-2. Temper-2. Lubricationlubricatingof electricatureatureinformationoilpowerinformation3. Current3. Process2. Extent of3. Quality3. Valveinformationpollution ofinformationinformationworking oil3. Extent ofpollution ofcoolingwater
With the recent expansion of the asset management concept, Enterprise Resource Planning (ERP), Enterprise Asset Management (EAM), and Computerized Maintenance Management System (CMMS) are utilized to manage and monitor information about production plants. However, a total control system has not yet come onto the market.
In recent years, facility management has been mainly trending toward the management of assets rather than facilities over the total lifecycle of the assets based on the extension of the range of facilities and management regions instead of a conventional management method, which is focused on the maintenance and operation of facilities. In addition, facility management has been trending toward increased integration and connection with legacy information systems, such as the ERP, MES, and PLM.
In facility management in the past, it has been an object to reduce operating costs by reducing facility maintenance cost based on increasing productivity. In facility management based on EAM, on the other hand, a concept of realizing profit from facilities is pursued, which is different from the existing facility management system.
In the 2000s, EAM became a fundamental concept for developing and operating a computer-aided facility management system, which is an improved management system that is an incremental development over the existing CMMS. In recent years, asset lifecycle management (ALM), which is a concept of performing management over the entire lifecycle of enterprise assets by extending the range of EAM, has come into existence.
In order to introduce maintenance technique based on CBM, sequential application is necessary based on the level of the existing system. Specifically, three classes of CBM systems may be introduced.
First, a simple CBM system, CBM3, is the least expensive CBM system, and periodically diagnoses the state of facilities in a simple fashion through inspection using the five senses or using a simple portable diagnostic instrument, thereby determining maintenance actions.
Next, an intermediate CBM system, CBM2, is the best known CBM system, and represents an expansion of the simple CBM system to periodically diagnose the state of facilities using a precise diagnostic instrument, i.e. a system that determines a maintenance policy based on periodic simple diagnosis and periodic precise diagnosis.
Finally, a high-class CBM system, CBM1, is a high-grade CBM system that includes continuous facility monitoring having an automatic diagnosis function. The CBM system CBM1 is used only for high-priced critical machines. At present, leading foreign diagnosis and control companies are manufacturing high-class CBM systems.
In order to apply the above-described CBM system to offshore plants that have been used for more than 30 years, however, it is necessary to develop a system that is capable of supporting asset information management and communication based on international standards. Specifically, a new concept surpassing the high-class CBM system is needed.
In the conventional systems, high operation and maintenance costs are required due to operation for a long time, and damage and accidents may occur due to human error, inexperienced inspectors, or the like. For these reasons, there is a high necessity for securing and localizing original technology for condition based maintenance.
An example of the related arts is disclosed in Korean Patent Application Publication No. 10-2011-0129276 (published on Dec. 1, 2011) entitled “AUTOMATED MAINTENANCE SYSTEM FOR FLOATING TYPE STRUCTURES.”
Another example of the related arts is disclosed in Korean Patent Application Publication No. 10-2013-0114515 (published on Oct. 18, 2013) entitled “SYSTEM AND METHOD FOR STATICALLY AND DYNAMICALLY POSITIONING OFFSHORE STRUCTURE USING REAL-TIME MONITORING OF SIX DEGREE OF FREEDOM MOTION OF THE POSITIONING OFFSHORE STRUCTURE.”
Another example of the related arts is disclosed in Korean Patent Application Publication No. 10-2012-0085223 (published on Jul. 31, 2012) entitled “AUTOMATED MAINTENANCE SYSTEM FOR FLOATING TYPE STRUCTURES.”
A further example of the related arts is disclosed in Korean Patent Application Publication No. 10-2014-0025803 (published on Mar. 5, 2014) entitled “SYSTEM AND METHOD FOR MAINTAINING DYNAMIC POSITION OF FLOATING OFFSHORE STRUCTURE.”